What follows are Jim's instructions for imaging and processing color images using the Share the Skies telescope Make sure the image is centered using a short grayscale shot. Then turn on color, and configured the shots as follows:(specific to the Trifid series) Luminance:1 x 1 binning (so I can reduce the size later, which improves the image quality) 3 x 120 seconds, with autodark Red, green and blue are set to 2 x 2 binning for greater sensitivity and quicker download Each 3 x 120 seconds with autodark Once the exposure is done I download the pix Then bring them into CCDOps (from SBIG) -use the “median combine 3 images” function to open and combine each triplet -once I have the combined image, I filter for hot and cold pixels - I do a auto contrast stretch, but I make it a couple steps darker than the automatic so it won’t over saturate -I the fixed combination shots as tiff files so I can open them in ImageJ (poor man’s Photoshop) -I reduce the size of the luminance frame to half, so it will match the others.It always looks better after this step I open each shot in ImageJ, and combine into a stack. Then register the stack so the stars line up on all frames. Next, unstuck the images and use the “RGB merge” function to combine the frames. I always have to play around with the color layers and brightness / contrast at this point, but I end up with a composite image. Basically, that’s it!
What follows are Jim's instructions for imaging and processing color images using the Share the Skies telescope
Make sure the image is centered using a short grayscale shot. Then turn on color, and configured the shots as follows: (specific to the Trifid series)
Luminance: 1 x 1 binning (so I can reduce the size later, which improves the image quality)
3 x 120 seconds, with autodark
Red, green and blue are set to 2 x 2 binning for greater sensitivity and quicker download
Each 3 x 120 seconds with autodark
Once the exposure is done I download the pix
Then bring them into CCDOps (from SBIG)
-use the “median combine 3 images” function to open and combine each triplet
-once I have the combined image, I filter for hot and cold pixels
- I do a auto contrast stretch, but I make it a couple steps darker than the automatic so it won’t over saturate
-I the fixed combination shots as tiff files so I can open them in ImageJ (poor man’s Photoshop)
-I reduce the size of the luminance frame to half, so it will match the others. It always looks better after this step
I open each shot in ImageJ, and combine into a stack. Then register the stack so the stars line up on all frames. Next, unstuck the images and use the “RGB merge” function to combine the frames.
I always have to play around with the color layers and brightness / contrast at this point, but I end up with a composite image.
Basically, that’s it!
Done here? Go back home.